1. Field of the Invention
The present invention relates to check valves for one-way flow control and pressure relief within tubing, and in particular to check valves which may be anchored in place through the use of a barbed casing and check valves including components having a straightforward and simple design allowing the components to be scaled down to an extremely small size without losing functionality or performance of the check valve.
2. Description of the Related Art
Check valves are used in a wide variety of applications to provide accurate, reliable one-way fluid flow control and pressure relief. Applications in which check valves are typically used include medical diagnostic and treatment equipment, gas analysis equipment, filtration, beverage dispensing, semiconductor fabrication, chemical processing and many others.
While many configurations are known, a typical check valve is comprised of an annular disc, or poppet, mounted for axial translation within the cavity of a housing. A biasing mechanism such as a spring is provided to bias the poppet into a sealing position which prevents fluid flow through the valve. When mounted in a pipe, tubing or other fluid flow conduit, fluid flow acting on the poppet in the same direction as the force exerted by the biasing mechanism further increases the pressure on the seal to prevent fluid flow in that direction. On the other hand, fluid flow of sufficient pressure acting on the poppet in the opposite direction as the force exerted by the biasing mechanism overcomes the force of the spring to move the poppet out of its seat to thereby create a path for fluid to flow through the valve. The pressure at which fluid overcomes the force of the spring to unseat the poppet and allow flow through the valve is referred to as the cracking pressure.
One problem in conventional check valves relates to mounting the valve within the flow conduit. Conventional valves that are merely seated in a pipe or tubing tend to dislodge and move under fluid pressure. While it is known to machine a cavity into the conduit for seating the valve, such machining is adds time and expense to the provision of the valve.
Another problem with conventional check valves is that the moving parts are not easily scaled down for small inner diameter (“id”) conduits. As the applications in which check valves are used call for smaller and smaller conduit ids, redesign of the check valve has become necessary.